River Rock Calculator
River rock is priced by the ton but spread by the inch. Enter the area you are covering and the stone size, and this gives you the weight to order.
How the math works
Volume = length x width x depth in feet, divided by 27 for cubic yards. Weight = cubic yards x about 2,600 pounds, divided by 2,000 for US tons. Larger stone weighs a little less per yard because the gaps between the stones are bigger.
Common questions
- How much does a yard of river rock weigh?
- About 2,600 pounds, so roughly 1.3 tons. Smaller stone packs tighter and runs closer to 2,700 pounds; large cobble has bigger gaps and runs nearer 2,400.
- How deep should river rock be?
- Two to three inches for one inch stone, three to four for two inch stone, and six for cobble. The rule is roughly twice the stone size, otherwise the ground shows between the rocks.
- How much area does a ton of river rock cover?
- At two inches deep a ton covers roughly 80 to 100 square feet. At four inches it covers about half that.
- Do I need fabric under river rock?
- Yes. Without it the stone works its way into the soil within a couple of seasons and you end up buying it twice. Use a woven landscape fabric, not plastic sheeting, so water still drains.